Intensive Care Medicine

, Volume 37, Issue 9, pp 1494–1500

A physiologic comparison of proportional assist ventilation with load-adjustable gain factors (PAV+) versus pressure support ventilation (PSV)

  • R. Costa
  • G. Spinazzola
  • F. Cipriani
  • G. Ferrone
  • O. Festa
  • A. Arcangeli
  • M. Antonelli
  • R. Proietti
  • G. Conti
Original

DOI: 10.1007/s00134-011-2297-y

Cite this article as:
Costa, R., Spinazzola, G., Cipriani, F. et al. Intensive Care Med (2011) 37: 1494. doi:10.1007/s00134-011-2297-y

Abstract

Purpose

To compare patient–ventilator interaction during PSV and PAV+ in patients that are difficult to wean.

Methods

This was a physiologic study involving 11 patients. During three consecutive trials (PSV first trial—PSV1, followed by PAV+, followed by a second PSV trial—PSV2, with the same settings as PSV1) we evaluated mechanical and patient respiratory pattern; inspiratory effort from excursion Pdi (swingPdi), and pressure–time products of the transdiaphragmatic (PTPdi) pressures. Inspiratory (delaytrinsp) and expiratory (delaytrexp) trigger delays, time of synchrony (timesyn), and asynchrony index (AI) were assessed.

Results

Compared to PAV+, during PSV trials, the mechanical inspiratory time (Tiflow) was significantly longer than patient inspiratory time (Tipat) (p < 0.05); Tipat showed a prolongation between PSV1 and PAV+, significant comparing PAV+ and PSV2 (p < 0.05). PAV+ significantly reduced delaytrexp (p < 0.001). The portion of tidal volume (VT) delivered in phase with Tipat (VTpat/VTmecc) was significantly higher during PAV+ (p < 0.01). The time of synchrony was significantly longer during PAV+ than during PSV (p < 0.001). During PSV 5 patients out of 11 showed an AI greater than 10%, whereas the AI was nil during PAV+.

Conclusion

PAV+ improves patient–ventilator interaction, significantly reducing the incidence of end-expiratory asynchrony and increasing the time of synchrony.

Keywords

Patient–ventilator synchrony Proportional assist ventilation Pressure support ventilation 

Copyright information

© Copyright jointly held by Springer and ESICM 2011

Authors and Affiliations

  • R. Costa
    • 1
    • 2
  • G. Spinazzola
    • 1
  • F. Cipriani
    • 1
  • G. Ferrone
    • 1
  • O. Festa
    • 1
  • A. Arcangeli
    • 1
  • M. Antonelli
    • 1
  • R. Proietti
    • 1
  • G. Conti
    • 1
  1. 1.Department of Intensive Care and AnaesthesiaCatholic University of Rome, Policlinico Agostino GemelliRomeItaly
  2. 2.Department of Anesthesiology and Intensive Care MedicineUCSCRomeItaly